Project
Diesel

On September 2, 1998, with Don Wood as backup, I tried a
mixture of diesel and ammonium nitrate. The video isn't very
interesting, but here is the audio of that failure (AwCrap.wav -- a 280 Kbyte WAV file).
Don did the video taping and was the inspiration for the title of
the files. The tin can bouncing and rolling sound you hear in
the background was an empty pop can rolling off the hood of my
pickup. The muzzle blast from my 30.06 knocked it off. We were
using the hood for a benchrest for the rifle and video camera. We
tried two pop cans full of this, with the same result --
disappointment.

I went back out the range again with Don Nelson a while later to do some more
tests. Here is one of the videos obtained
then.

And to answer a question from a couple different sources, here
is what happens when you put it in a six ounce juice can (SmallCan.wmv 374 Kbyte
WMV file).
Of course there were a couple other variables changed too. The
percentage of potassium chlorate was reduced, and the AN was not
ground up like it was in the first case.

The recipe I ended up using for the first Boomershoot was:

2 cups prilled (NH4NO3)
1 cup KClO3
1/4 cup diesel

Both the ammonium nitrate and KClO3 were ground up
(but NOT together). The diesel was mixed with the NH4NO3
then the KClO3 was added.

I still have some more work to do. I would like to make the
targets cheaper and more sensitive. They cost about
$1.00/target currently and if the velocity of a .30 caliber
bullet gets below about 2200 fps they sometimes don't go
off. I think it may be ambient temperature related
too. I suspect that what is actually going on is that at
impact time the ammonium nitrate and potassium chlorate combine
to produce ammonium chlorate, which explodes at a temperature of
102 C. If true, then the optimum mixture is something a
little richer in KClO3 than what I was using.
This might make things more sensitive. Other options to try
include using various catalysts for the reaction. I have some on
order and hope to try them out soon. Another thing that I think
will be a good idea is to use half-pint milk cartons instead of
the pop cans. This will be much easier to fill, less danger
from shrapnel, and make a lost target more likely to decompose
safely in a week or two rather than wait around for years for
some kid to find it or end up as some sort of crude land mine,

For those that have the access to the chemicals and a legal
location to do this sort of thing I suspect the best recipe for
this, that I know for certain will work, is 55% KClO3,
36% NH4NO3 and 9%
diesel/kerosene/fuel-oil/etc. All the percentages are by
weight. I believe the safest method of mixing is to grind
up the KClO3 separate from the NH4NO3,
(both should be very fine) mix the diesel and NH4NO3
together, then add in the KClO3. Use all the normal
precautions for working with explosives and chlorates in
particular. Small batches, face shields, body armor, heavy
gloves, ear protection, clean work environment, no sparks or open
flames, no wooden or iron/steel tools, be extremely careful about
friction and impact, test for friction, impact, and spark
sensitivities with very small samples, dispose of all left over
finished product in a timely and safe manner, and probably a
hundred other things that I just do without even thinking about
it and you must learn in order to be safe too. Some of the mixes mentioned
below have not been stored for more than a couple days so I don't know but
what it may spontaneously explode after 72 hours. I have
also read cautions about working with KClO3 in the
presence of direct sunlight and have done all my work in the
shade. There are cautions in the literature about moisture
with the ammonium salts and KClO3. Keep your chemicals
dry and remember that NH4NO3 will absorb
moisture from the air. Probably in sufficient quantities to
cause problems. Be sure to follow all the ATF rules on proper
distances from occupied buildings, roads, etc. See
http://www.atf.gov/explarson/fedexplolaw/2007edition/index.htm
for a start. Also, if you are stupid enough to engage in
recreational explosives and get yourself arrested, hurt,
killed, or a combination thereof, the extent of my liability will be to nominate you for a
Darwin Award. And always remember:

There are old pyros,
and there are bold pyros,
but there are not very many
old, bold pryos.

If you really want to get involved I suggest you let someone
else do it (I plan on having a shoot each spring) or
read a bunch of books on the subject before you start.

Project
Diesel II

Three goals with this project, in the following order.
1) Reduce the risk, 2) Increase the sensitivity, 3) Reduce the
cost per target. I had been used aluminum soda cans, metal
being "a bad thing" to have explode in your vicinity
should an accidental detonation occur. Also, a lost can
would probably hang around for years without deteriorating and
become a hazard if someone were to decide to recycle it or
whatever. The mixture isn't quite sensitive enough to be
reliably detonated at great distances. Perhaps even with
.223 rounds on cold days at short ranges. Not good.
The mixture I used in the October '98 event cost about $1.00 per
target about $0.90 of that was KClO3.

I have switched to half-pint paper milk cartons for the
containers. These should be safer in the event of an
accidental detonation and they should deteriorate within a few
days (weeks?) in the sun and weather. Once exposed to the
rain the NH4NO3 should dissolve into the
ground and completely eliminate the hazard of an accidental
explosion. Also, the cartons open wide enough to make it
easier to load than the soda cans. Folding them into
roughly a cube and sealing them with glue and tape should make
for a relatively good target.

In an effort to reduce the cost of the targets and increase
the sensitivity I obtained some MnO2 which is used as
a catalyst with KClO3 (in the presence of MnO2,
KClO3 breaks down to release it's oxygen at about 70 C
rather than the usual 400 C). I was hoping it would also catalyze
NH4NO3 (ammonium nitrate). On February 27,
1999 I mixed up some NH4NO3 with diesel (ANFO) in the usual proportions (diesel is about 5.5% by weight)
and added about 1% MnO2. I took a very small quantity
and rubbed (hard) it between the face of a hammer and a metal
plate. Nothing. I light tapped it between the face of two hammers
-- nothing. Tapping harder finally got a small snap occasionally.
This is more than I can get to happen with ANFO by itself. I
added about 1 % SiO2 (sand) to increase the friction.
About the same. I burned a small amount of it. Nothing much, it
didn't burn very well. I added about 2 % KClO3 to the ANFO, MnO2, SiO2 mixture. Rubbing didn't do
anything, tapping lightly got snaps fairly frequently with
occasional "good ones". Burning was about like a
burning a match head for a similar size piece. Similar experiment
using Fe2O3 as the catalyst. Similar
results but probably just a bit less reactive. These tests
indicate that it probably is safe for mixing, static and fire
hazards, and putting in the target containers.

Out to the range the next day (February 28, 1999). The
temperature was about 40 F, which I suspect affects the results.
Higher temperatures making it more likely to detonate. I forgot
to bring the KClO3, but I was mostly interested in
seeing if I could get things to detonate without the use of KClO3
anyway. I mixed some of the stuff by volume (no scales at the
range), 1 cup ANFO, 1/2 teaspoon MnO2, 1/2 teaspoon
SiO2 inside a half-pint milk carton. This should
figure out to be about 1 % MnO2 and 1 % SiO2. I put two .22 LR
rounds through it from 30 yards away. 9.5 feet from the muzzle they
were 910.7 and 1116 fps (yeah, I know, crappy ammo). Nothing. One
round of 7.62 x 39 at 2236 fps at the chronograph. Nothing. I
switched 7.62 x 39 ammo getting 2366 fps (an estimated 2300 fps
at the target). Nothing except the box was torn up so badly there
wasn't much material left in it.

I ran out of time (and being a "cop magnet" I got a
speeding ticket on the way home -- 57 in a 45 MPH zone...), but I
now know that ANFO, MnO2, and SiO2 combined
won't detonate with rifle fire. At least not at target velocities
of <= 2300 fps at 45 F. Next time I'll try adding some small
quantities of KClO3. Maybe I can get detonation with
much smaller quantities of KClO3. And I suspect
that as I increase the amount of KClO3 the sensitivity
will increase. I'll increase it until a supersonic .22 LR
will set it off, but a subsonic round will not. At least
that is my plan.

Other possible catalysts for the NH4NO3
include potassium dichromate, and ammonium dichromate. But
they are both rather poisonous. I have some on order and if
the benefit is worth the additional hazards I'll give it serious
consideration and a full report here.

I did some very small scale experiments with the potassium
dichromate and ammonium dichromate. I mixed up about a
teaspoon of the mixtures and did friction and impact tests with
hammers and steel plates. It didn't seem (I know -- very
subjective) nearly as good using the MnO2 as a
catalyst.

April 11,
1999 Update:

I finally got out to the range with the MnO2
catalyzed mixture. Fred and Mike hung around after the NRA
Personal Protection Class I taught and helped with the video,
shooting (Fred supplied his .22 pistol and ammo), and offered
helpful suggestions. And most importantly they were
available to check and see if there were enough piece left of me
to consider calling an ambulance should I have an accident.

The NH4NO3 was ground up in a blender
into fine sand sized particles the night before and sealed from
contact with air for combining with diesel and other stuff on the
range. The assumed specific density for the various
components are:
NH4NO3 : 0.90
KClO3 : 0.93
MnO2 : 1.32
Diesel : 0.82
C10H8 : 0.54

Yes, I know, I should be using mass, not volume with the
powders. But it's tough to do out on the range. None
of the powders were packed, all were fluffy, like you would do
with flour, in the kitchen, making bread.

Mix 1:
I mixed up 600 mL of NH4NO3 with 40 mL of
diesel and 22 mL of mothball flakes (naphthalene, C10H8).
In a separate bowl I mixed 100 mL KClO3 with 10 mL of
MnO2 and 0.5 mL of baking soda. Then the two
mixtures were combined. The hypothesis of using some C10H8
was that it would sublime in the milk carton creating a vapor
that would be easily ignited with the free oxygen from the KClO3
and the NH4NO3 . This reduced the
amount of diesel required which I suspect reduces the amount of
heat required to get the mixture up to temperature (assuming
temperature is the triggering physical event). This is
very, very lean on the KClO3 compared to what I used
last year, about one fourth as much. The cost per target
would be in the $0.50 range. I called this my "lean
mixture". The baking soda was to reduce the chance
that acids would form and cause spontaneous decomposition from
the breaking down of the KClO3 . This was
suggested by one of the fireworks books I have been reading on
working safely with the chlorates.

This mixture was put into three 1/2 pint milk cartons with 200
grit aluminum oxide sandpaper on the back inside surface. A
fourth carton without sandpaper was filled also. The
cartons were taped shut and put on the berm about 30 yards
away. At least one solid hit was made with a .22 LR from
both a pistol and a rifle without anything more interesting than
puffs of dust. Out came the .223 with 62 grain FMJ
ammo. These are a little slow in this short barreled gun,
about 2490 fps at the target. They didn't do anything
noteworthy either. Next came the 50 grain ammo using
Hornady VMAX
bullets. These bullet clocked in at about 2860 fps at the
target. This detonated everything. Even the milk carton
without the sandpaper. Here is the video snippet from this
first carton of the "lean
mixture" we got to detonate. Fred was just kidding
of course... :-)

Mix 2:
The first mixture was rewarding, but not satisfactory. This
would cut the price of the targets in half and obviously it's
fairly safe. But the requirement of the higher speed
bullets (also expanding rather than FMJ -- what was it that made
the difference?) is unacceptable. Next I mixed up 500 mL of NH4NO3
with 60 mL of diesel. In a separate bowl I mixed 200 mL
KClO3 with 10 mL of MnO2. Then the
two mixtures were combined. The difference from before is a
higher percentage of KClO3, no C10H8,
and no baking soda. I really should have put in the C10H8
with less diesel, but I was in a hurry. This mixture was
also put in cartons with sandpaper. Again the .22 LR ammo
wouldn't do anything. The 62 grain .223 ammo got some smoke
out of one of the cartons and the 50 grain VMAX bullets detonated
it. No difference between sandpaper and not (the one that
smoked was sandpaper, however another one that didn't smoke also
had sandpaper).

Mix 3:
Next was 200 mL NH4NO3 with 25 mL of model
racing fuel (45% nitromethane CH3NO2 plus
methanol and lubricating oil). In a separate bowl I mixed
33 mL KClO3 with 3 mL of MnO2. Then
the two mixtures were combined. I think I may have screwed up on
the racing fuel. I hadn't (and still haven't) done the
proper chemical balance stuff to make sure I have the right
percentages. There was a little smoke with the 50 grain
VMAX bullets, but no detonation. One of my helpers believes
he can get some pure nitromethane. This would help with the
chemical balance problem (who knows what the percentage of
methanol and oil is and the type of oil?). Also, it's the
CH3NO2 that is of interest to me.
Supposedly, when hot, this will explode from impact without
additional chemicals. It is a bit expensive though.
See MSDS
for more information on it.. No time to explore this before
the Boomershoot later this month, but maybe for the next.

Mix 4:
Next I mixed up 200 mL of NH4NO3 with 32 mL
of diesel. In a separate bowl I mixed 150 mL KClO3
with 5 mL of MnO2. Then the two mixtures were
combined and put into 1/2 pint milk cartons without sandpaper. I
called this my "rich mixture" because of the high
concentration of KClO3 . Approximately the same
percentages as last year with the addition of MnO2 for
a catalyst. Again the .22 LR ammo would not get any
results. But the 62 grain FMJ (2490 fps target velocity)
bullets reliably set everything off with a very satisfying thump
to the chest. Here is the video from the first of this
mixture, my "rich mix".
I hadn't really realized it until this last test of the mixture
that the previous ones were not giving as much "thump"
as the first. And the echo's from the surrounding hills
that continued for a surprisingly long time also gave evidence
that this was a much different result than previous
mixtures. Fred made a comment about it giving a quite a
"wallop". Then Mike and I discussed it a bit more at
length. Both of us were quite sure that this last mixture
resulted in by far the most satisfying explosion.

Conclusion:
More tests are needed. I still haven't reduce the cost, nor
have I increased the sensitivity enough that a just supersonic
.22 caliber bullet can detonate it. I have confirmed that
1/2 pint milk cartons can be used which should increase the
safety some. I have also confirmed that adding the MnO2
does not make the mixture super sensitive to the point of an
extreme safety hazard.

June 3, 1999
Update:

Just so people know what I used (and I don't forget
too!) for the April 25, 1999 event. I would put 2 1/4 cups
of NH4NO3 and 1/4 cup of mothball flakes in
the blender and grind it up for about 45 seconds. Then I
would put that in a mixing bowl and add 1/4 cup of diesel.
Then I would put 2 1/4 cups of KClO3, 1/2 tsp MnO2
and 1/2 tsp baking soda in the blender and let it grind
while I was mixing 1/4 cup diesel into the NH4NO3/C10H8
mixture. After the KClO3mixture
was done I would stir it into the NH4NO3.
Then the stuff was put into the 1/2 pint milk cartons (makes
about 5) and closed up with tape.